Semi-automatic code sender



Aug. 3%, 196% J. D. FRIEDMAN SEMI-AUTOMATIC com: SENDER 3 Sheet s-Sheet 1 Filed Aug. 6, 1958 Aug. 30, 1960 'J. D. FRIEDMAN SEMI-AUTOMATIC cons SENDER 3 Sheets-Sheet 2 Filed Aug. 6, 1958 Fig.3

Fig.4

I! I. IE: I

II .II I. ll Jerome D. Friedman I INVENTOR.

Mara. BY MW 25% 1950 J. D. F'IQIEDMAN 2,951,122

SEMI-AUTOMATIC CODE SENDER Filed Aug. 6, 1958 3 Sheets-Sheet 3 Fig.7

I24 I20 I92 i'ELEGRRPH KEY [007 I? SHE W YJ Jerome D. Friedman 1N VENTOR.

Waugh... BY ym/0y 8M U] 1 i a. -a'. a:

United States Patent 1 SEMI-AUTOMATIC CODE SENDER Jerome D. Friedman, Topeka, Kans. (55th Air Refueling Squadron, A.P.0. 864, New York, N.Y.)

Filed Aug. 6, 1958, Ser. No. 753,466

12 Claims. (Cl. 178-84) This invention relates to communications and particularly to a simple teletype machine to be used Where the cost of commercially available equipment is prohibitive, for example, as an aid to learning Morse code.

The code sender that typifies the invention is mechanically simple and uses electrical circuitry in a low voltage system for achieving a number of results. The code sender is adjustable so that when individual keys of the sender are depressed, a signal which is pulsed in accordance with Morse code convention, is applied to a telegraph key to operate the key. When the sender is used for practice or for teaching, the signal transmission aspect of the circuit can be disconnected by opening a switch, leaving only a group of lamps which visually indicate the keys that are depressed by the student or by the person practicing. The signal lamps individually become energized as each key is depressed and remain energized so long as the key remains in the depressed position.

The code sender has a novel organizationof parts in the electrical circuit together with novel individual parts. For instance, the code sender constructed in accordance with the invention has a group of keys, each operating a normally open switch. When one of these switches is closed an electro-magnetically operative device, for instance a solenoid, is energized causing a code drum to be rotated through a partial revolution. .At the same time a mechanical drive connection between the code drumand a governor switch causes the governorswitch to be actuated. The governor switch is constructed so thatthe speed of the drum is maintained within a fixed tolerance. Since the drum has a plurality of contact patterns on it representing the Morse code, the switch that is closed will cause a part of that drum, specifically the dot and dash pattern corresponding .to the letter designation of the key depressed, to become energized. The code drum contacts wiping across a brush .delivers a signalto an output signal circuit for transmission to the telegraph key.

One of the features of the invention is a key continue light and the manner with which it is energized. The continue light becomes energized when the code drum reaches a predetermined point in its rotation, at which the contacts of the continue light switch are closed. The continue light switch, light and the resistor are connected in series, and this group of components are connected in parallel with the drumv actuation device. The resistor is a voltage limiting resistor assuring that .the electromagnetically operative device, preferably a solenoid, will have sufficient voltage to operate it.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a perspective view of a code sender constructed in accordance with the invention showing one possible configuration of the console cabinet.

Figure 2 is a sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a sectional view taken on the line 33 of Figure 2.

Figure 4 is a sectional view taken on the line 4-4 of Figure 2.

Figure 5 is a sectional view taken on the line 5-5 of Figure 4.

Figure 6 is a sectional view taken on the line 66 of Figure 2.

Figure 7 is a diagrammatic view showing the electrical circuitry in the code sender.

Figure 8 is a perspective view of a wafer constituting part of the code drum.

In the accompanying drawings there is a code sender 10 that has a frame 12 made of a reasonable gauge metal and having a support 14 attached to the bottom 16 thereof. The frame has a console panel 18 with a number of openings '20, an inclined front wall 22, a top wall 24, together with end walls and a back wall.

Code drum 28 is mounted in bearings that are carried by the parallel end walls 30 and 32 of support 14. The drum 28 can be constructed in a number of ways, such as being cast in one piece or being built up on a spindle 34. In the latter case the drum is made of a plurality of wafers, such as water 36 and these can be placed with their fiat faces confronting each other on spindle 34 or can be uniformly spaced by means of spacers on the spindle and between wafers. Regardless of the structural details, the surface of the code drum has a number of contacts, such as contacts 38 and 40 on wafer 36. The contacts with the small frontal area represent dots in Morse code, while the contacts such as contact 40, having a larger surface area, represent dashes in the same code. Each wafer will have'a different pattern of contacts in order to represent each letter of the alphabet, the usual numerals and punctuation marks and any other code representations that are normally used in telegraphy or in specialized adaptations thereof. One of the wafers 44 (Figure 5) has a long contact 46 for continual engagement with brush 48 during rotational movement of the code drum 28. This will be described in more detail as to its function subsequently.

Spindle 34 has an arm 50 (Figure 2) attached to it, and this arm is secured to an arcuate ar-mature52 of solonoid 54, the latter being an electromagnetically operative device for rotating the drum. The solenoid coil is in the solenoid casing 56, the latter bolted or otherwise secured to wall 30 of support 14. Spring 58 is concentrically dis posed on the arcuate armature 52 and seats on arm 50 as Well as a part of casing 56. This spring opposes the solenoid armature movement in one direction, returning arm 50 after the solenoid has rotated the .code drum 28 for each cycle of drum operation. Bumper :64 is located in the path of travel of arm 50 and consists of a spring 66 mounted on a plunger 68 whose travel is constrained by fitting in a passage in the base 70 of .the bumper. The spring bumper could be substituted with a dashpot-or a similar device so long as the shock absorbing necessary for arm 56 is obtainable.

As the drum 28 rotates, it drives gear segment 72 that is attached to wafer 44 or some other .part of the drum. The gear segment is enmeshed with pinion 74 on shaft 76, and this is attached to rotor 78 of governor switch 80. The governor switch is attached, for instance by a mounting bracket 82, .to .the end wall 36 of support 14, and functions to assure that drum 28 is operated at a preselected speed, uniform 'for each oscillatory cycle of operation.

Rotor 78 is made of a conductive ring-84 on the periphery of an insulating disk 86 to which shaft 76 is fixed. Radial conductor 88 is attached to shaft 76 and has its end at the outer surface of disk 86. A spring loaded contacter 90 is disposed in cage 92, this cage also radially mounted and in alignment with conductor 88. Spring 94 in cage 92 has its compressive load adjustable by set screw 96 that is carried by cage 92 and which reacts on spring 94. Adjustment of the set screw will cause the ball contactor 90 to be pressed against conductor 88 with varying degrees of force.

As the governor switch 80 is rotated, if a preselected speed is exceeded, centrifugal force moves the contacter 90 radially outward from the axis of rotation of the governor and this breaks a circuit that includes solenoid 54. The breaking of the solenoid circuit causes the solenoid to be deenergized, and the speed of the governor is at once reduced thereby correspondingly reducing (the centrifugal force acting on spring loaded contacter 90. The result is that the contacter will again engage conductor 88, close the circuit with solenoid 54 and further energize the solenoid. The making and breaking of the switch part of the governor 80 is done exceedingly rapidly. I

The panel 22 has two switches 98 and 100. The switch 98 is merely an on-olf switch, while switch 100 controls an output signal circuit 102 (Figure 7) which is used in addition to an illuminated indicator panel 104 (Figure 1) or left idle while the panel 104 is being used. The output signal circuit yields an electrical signal that pulses in accordance with Morse code convention and is responsive to the particular key 106 in the keyboard, that is depressed. Output signal circuit 102 has an impulse converter 108 (Figure 2) constructed of a frame 110 carried by the base 16 and supporting an electromagnet 112. Leaf spring contact 116 is attached to frame 110 and has a contact point 118 attracted by the armature of electromagnet 112. Another part of the leaf spring contact has switch points 120 and 122, the switch point 122 being fixed to frame 110 and the switch point 120 being movable since it is carried by leaf spring contact 116. The switch points 120 and 122 are adapted to be connected by conductors 124 and 126 to a telegraph key by attaching parallel thereto. Switch 100 is in the conductor 126 so that the entire output signal circuit 102 is controlled by switch 100.

The keys 106 of the keyboard each has a switch 130 that is normally open. A typical switch 130 is a three terminal switch of the type used for a large number of years in teletype machines. All contacts remain open when the switch is in the rest position, with spring 132 reacting on the switch operator to hold the switch open. When typical key 106 (Figure 2) is depressed, the inward movement of the switch operator 134 is opposed by spring 132, and the switch is closed thereby completing a circuit which will be described as the description of the operation of the code sender is described in full. Each of the switches 130 has a conductor, for instance see typical conductor 136 in Figure 7, extending from the switch beneath the letter Z. In addition each switch has a signal lamp 138 in a socket (unshown) and mounted behind panel 104 and for the example under discussion, directly behind the letter Z on the panel. Brush 140, which may be constructed of a spring metal finger attached on an insulating bar 142 of support 14, is connected with conductor 136 in any accepted manner for instance by soldering or by a binding post. Brush 140 is adapted to wipe over the periphery of wafer 144 of drum 28, this wafer having contacts thereon that are shaped to deliver Morse code pulses in accordance with the Morse code convention for the letter Z. When the letter Z is transmitted, lamp 138 is energized so that this may be seen as an aid for training.

. A continue lamp 150 is in a socket 152 in panel 22. A continue switch 154 is attached to support 14 (Figure and is wired in series with lamp 150 and a voltage limiting resistor 156. Switch 154, lamp 150 and resistor 156 are connected in parallel with solenoid 54 so that when the solenoid is energized, lamp is energized, providing that switch 154 is closed. The purpose of the continue lamp is to inform the operator that the drum has completed its cycle of operation and the operator is free to depress another key to send another code signal by again initiating another cycle of operation. Accordingly, switch 154 is normally open, but is closed by a mechanical expedient. Pin 160 is attached to the end wafer 44 of the drum, and the switch 154 is located in the path of travel of the pin 160. Therefore, when the drum has traveled a predetermined distance, pin 160' engages the switch contacts of switch 154, closing them and completing the portion of the circuit having continue light 150 therein. The resistor 156 is a voltage limiting resistor enabling suflicient energy to enter the coil of solenoid 54 for complete and proper attention of the code drum 58.

A source 164 of electrical potential, for example a low voltage D.C. source, is connected to conductor 166 having switch 98 therein. This controls the entire circuit of the sender. Conductor 166 is used for energizing a network that connects to two terminals of each switch 130. For instance refer again to the letter Z of Figure 7 where conductors 170 and 171 constitute part of this network and are attached respectively to buses for split leads of conductor 166 and to two terminals of switch 130 for the letter Z. The other terminal of the same switch 130 for the letter Z has conductor 136 attached to it. All other switches 130 are connected in the same manner. Conductor 166 after feeding all of the switches 130 is attached as a network connection to conductor 174, the latter terminating in a brush 176 that is in contact with shaft 176 of governor switch 80. Brush 180 is in contact with ring 84 and is attached to conductor 182. A spark softening capacitor 184 is connected across conductors 174 and 182 in order to materially reduce, if not prevent, arcing in the governor switch 80. Conductor 182 is connected in series with solenoid 154 and with the continuous light switch 154, lamp 150 and resistor 156. Accordingly, the conductor is connected with this same group of parts and terminal 192, arbitrarily considered the negative side of source 164. The positive terminal 194 is connected to conductor 166.

The entire drum 28 is conductive and has brush 48 connected with it by contact with wafer 44. Conductor 196 extends from the brush 48 and is connected with terminal 192. However, solenoid 112 is wired in series with the brush 48 so that the solenoid coil is pulsed each time that the drum 28 conducts. Accordingly, circuit 102 is energized and deenergized in accordance with the pulse transmission that is controlled by the drum 28. Switch 100 makes it possible to render circuit 102 ineffectual in accordance with the desires of the user.

After switch 98 is closed the operator can select any key and depress it. The switch 130 with which the key is operatively connected is then, the only switch 130 in the closed condition. Current flows, arbitrarily assuming, from terminal 192 through conductor 190 and solenoid 54. This rotates drum 28 with switch 154 open. Accordingly, as the drum is being rotated, the continuous light switch 154 does not conduct so that continue light 150 is deenergized.

Governor switch 80 is wired in series with solenoid 54, so that if the speed of the code drum 28 exceeds a selected preset level, the switch part of governor 80 instantaneously opens, instantaneously breaking the circult to solenoid 54 and slowing the operation of the drum. As the speed decreases, the switch part of governor 80 again closes so that the solenoid can continue to operate.

Current flows from the governor switch 80 through conductor :174, the network fed by conductor 174 and returns to the positive terminal 94 through conductor 166 and switch 98.

The information applied to circuit 102 in the form of a signal, is taken from the contacts 38, 40 on the wafer that is energized and when a wafer construction is not used, from the contacts of drum 28. The current flows through the switch 130 that is depressed, the conductor 136 or the conductor corresponding to conductor 136 for whatever switch 130 is closed, through the lamp associated with that conductor and the brush attached to the same conductor. Drum 28 is conductive so that the current is carried through wafer .144, brush 48 and conductor 196 so that it can energize circuit 102 with pulse signals. The circuit 102 can feed a telegraph key by being wired in parallel therewith or can energize any other signal emitting device, for instance a lamp at a remote location. Each time that one of the contacts 38, 40 touches the conducting brush, the signal lamp associated with that brush becomes intermittently energized with long or short bursts of energy depending on whether a dot (contact 38) or a dash (contact 40) comes into engagement with the brush.

When the drum has completed its cycle, after rotating approximately 90, pin 160 closes switch 154 thereby energizing the continue lamp 150. This informs the operator that he is free to depress another key to transmit another letter, symbol, character, punctuation, etc., while spring 58 returns the solenoid 54 and drum 28 to the initial or rest position.

The foregoing is considered as illustrative only ofthe principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A code sender comprising a frame, a plurality of keys, a normally open switch for each key and carried by said frame, a code drum, a support on said frame and mounting said drum for rotation, a plurality of contacts on said code drum, brushes carried by said frame and located in the path of movement of said drum contacts, conductors attached to each brush and to each normally open switch, a speed responsive governor switch driven in unison with said code drum, a conductive network connecting each normally open switch with said governor switch, terminals adapted to connect with a source of electric potential, an electromagnetically actuated device drivingly connected to said code drum, means connecting one of said terminals and said device in series with said governor switch to govern the speed of said drum, means including said normally open switches and said network connecting said governor to the other of said terminals to thereby energize said device through said governor switch in response to actuation of any one of said keys.

2. A code sender comprising a frame, a plurality of keys, a normally open switch for each key and carried by said frame, a code drum, a support on said frame and mounting said drum for rotation, a plurality of contacts on said code drum, brushes carried by said frame and located in the path of movement of said drumcontacts, conductors attached to each brush and to each normally open switch, a speed responsive governor switch driven in unison with said code drum, a conductive network connecting each normally open switch with said governor switch, terminals adapted to connect with a source of electrical potential, an electromagnetically actuated device drivingly connected to said code drum, means connecting one of said terminals and said device in series with said governor switch to govern the speed of said drum, means including said normally open switches and said network connecting said governor to the other of said terminals to thereby energize said device through said governor switch in response to actuation of any one of said keys, an output signal circuit which includes said conductors and brushes and contacts and code drum and a wire extending from said drum and connected with the first-mentioned terminal.

3. The code sender of claim 2 and a solenoid energized by said output signal circuit and pulsed in accordance with the pattern of energized contacts of said code drum, and means for operatively connecting said solenoid to a telegraph key.

4. The code sender of claim 2 and a group of lamps for identifying said keys, and said lamp connected with said conductors.

5. A code sender comprising a frame, a plurality of keys, a normally open switch for each key and carried by said frame, a code drum, a support on said frame and mounting said drum for rotation, a plurality of contacts on said code drum, brushes carried by said frame and located in the path of movement of said drum contacts, conductors attached to each brush and to each normally open switch, a speed responsive governor switch driven in unison with said code drum, a conductive network connecting each normally open switch with said governor switch, terminals adapted to connect with a source of electric potential, an electromagnetically actuated device drivingly connected to said code drum, means connecting one of said terminals and said device in series with said governor switch to govern the speed of said drum, means including said normally open switches and said network connecting said governor to the other of said terminals to thereby energize said device through said governor switch in response to actuation of any one of said keys, a continue switch connected in series with a continue signal lamp and a resistor and connected in parallel with said device, said continue switch held open at the time when said device is energized, and means connected to said code drum for closing said continue switch when said code drum has been moved a predetermined distance.

6. A code sender comprising a frame, a plurality of keys, a normally open switch for each key and carried by said frame, a code drum, a support on said frame and mounting said drum for rotation, a plurality of contacts on said code drum, brushes carried by said frame and located in the path of movement of said drum contacts, conductors attached to each brush and to each normally open switch, a speed responsive governor switch driven in unison with said code drum, a conductive network connecting each normally open switch with said govern-or switch, terminals adapted to connect with a source of electrical potential, an electromagnetically actuated device drivingly connected to said code drum, means connecting one of said terminals and said device in series with said governor switch to govern the speed of said drum, means including said normally open switches and said network connecting said governor to the other of said terminals to thereby energize said device through said governor switch in response to actuation of any one of said keys, an output signal circuit which includes said conductors and brushes and contacts and code drum and a wire extending from said drum and connected with the first-mentioned terminal, a solenoid having a coil connected with said wire, a switch actuated by said solenoid, signal output conductors connected to said solenoid actuated switch, and a control switch connected in one of the last-mentioned conductors.

7. A code sender comprising a frame, a plurality of keys, a normally open switch for each key and carried by said frame, a code drum, a support on said frame and mounting said drum for rotation, a plurality of contacts on said code drum, brushes carried "by said frame and located in the path of movement of said drum contacts, conductors attached to each brush and to each normally open switch, a speed responsive governor switch driven in unison with said code drum, a conductive network connecting each normally open switch with said governor switch, an electromagn'etically actuated device drivingly connected to said code drum, means connecting one of said terminals and said device in series with said governor switch to govern the speed of said drum, means to thereby energize said device through said governor switch in response to actuation of any one of said keys,

an output signal, circuit which includes said conductors and brushes and contacts and code drum and awire extending from said drum and connected with the firstmentioned terminal, a solenoid having a coil connected with said wire, a switch actuated by said solenoid, signal output conductors connected to said solenoid actuated switch, and a control switch connected in one of the lastmentioned conductors, a lamp connected with each of said first-mentioned conductors and adapted to identify said keys.

8. The code sender of claim 1 wherein said governor switch includes a rotor, mechanical means drivingly connecting said rotor with said drum, a pair of spaced con tacts carried by said rotor, and a centrifugally opened contactor located between said spaced contacts.

9. The code sender of claim 8 wherein said contactor has a spring engaging it, andmeans for adjusting the compression of said spring.

10. A code sender, a conductive drum having a plurality of contacts thereon, a plurality of brushes in engagement with said contacts, a plurality of normally open key operated switches, conductors extending from said switches to said brushes, means responsive to closing of one of said switches for rotating said drum through a partial revolution, a speed governor switch in series with said drum rotating means, sign al lamp sockets operatively connected between said normally open switches and said brushes and adapted to be energized in response to en ergization of individual brushes.

' 11. In a code sender, a conductive drum having a plurality of contacts thereon, a plurality of brushes in engagement with said contacts, a plurality of normally open key operated switches, conductors extending from said switches to said brushes, means responsive to closing of one of said switches for rotating said drum through a partial revolution, a speed governor switch in series with said drum rotating means, signal lamp sockets operatively connected between said normally open switches and said brushes and adapted to be energized in response to encrgization of individual brushes, a continue signal lamp connected in parallel with said means for rotating said drum, means for controlling said continue signal lamp including a stop connected to said drum and adapted to close the continue signal lamp circuit when said drum has rotated to a predetermined position.

127 The sender of claim 11 wherein thereis an output signal circuit operatively connected with said drum, and means for controlling said output signal circuit.

References Cited in the file of this patent UNITED STATES PATENTS 

